Can't really answer your question straight on, but was steering wheel straight after alignment and did car track true then?

I would jack up right front wheel and check for play in right inner and outer tie rod ends first off by grapping wheel at front and back and see if there is any play in and out in either tie rod end. If none in tie rod ends but still some play see if there is any play (up down movement in right side mount of steering rack.

If no play in right wheel repeat process with left front wheel.

Report your findings.

 

Perhaps you happen on one of the "harmonic or resonant frequency" (of your car components) at those speed - in other words, things get worst when the sun, the moon and the stars all line up !

I would start with wheel balancing. You can try swapping both front wheels with both rear wheels and then one at a time to see whether you can identify the possibility of a "not balanced" wheel (a weight fell off?). Or, simply go get all four wheels re-balanced to see whether problem is still there. It is also possible that one of the tire is bad.

Another possibility is the brake. Jack up both front wheels and turn them one at a time to see whether there is any uneven spots.

The steering wheel is not centered and the car drifts is likely because the alignment guy simply didn't centered the wheel. If the toe-in is correct, one can loosen the tie-rod adjustments and adjust the same amount of on both side (in your case, shorten the right side and make the left side side longer). Depending how much the steering wheel is off, start with half or 1/3 of a turn on each side.

 

an out of round wheel (hit any potholes lately?) can also make for weird vibrations, which can sometimes be somewhat masked but not corrected with wheel balancing.

 

Vibration at specific speeds is typically a front wheel balance issue. Balance all around and get a good 4 wheel alignment and you should be set.

 

Thanks for all the input & suggestions, I will report back when I get this issue resolved.

 

I had this problem and chased it for months before the cause revealed itself when I parked with my front wheels turned almost to the limit with the sun illuminating the tread. Misalignment and failure to rotate caused the wheels to wear severely on one side and not much at all on the other. Same symptoms as you describe. New tires and complete alignment solved that.

Less than a year later, the car again pulls to the same side, but the alignment guru inspected the tie rods and tie rod ends and all the bushings and gave them the thumbs up back then. Doesn't mean the diagnosis would remain the same if performed again.

 

How are your brake rotors? Any vibration when applying the brakes?

 

Brakes are very good, no squealing or pulsating.

 

Sounds like a bent wheel or out of balance problem at least to start it off.

Jason

 

Well, had each front wheel jacked up and there is no play in the tie rods. Can't move the wheels at all in any direction. The front passenger side tire is worn unevenly on the inner edge. All the other tires are evenly worn. Looks like a bad alignment. I'll have to have it realigned and have the tires rotated.

 

I am not sure you will see an improvment vibrationwise with an alignment.

I would replace the 1 tire or pair, have it aligned and all wheel balanced.

If the vibration is still there, rotate and see if it changes feeling from front to rear.

Also hows the tire pressure??

I still suspect out of balance wheels or slight bend in one. I have had several bent wheels that gave me the same problem. Low speed nothing, 70-80mph vibration city! After 80, smooth again. Had the wheels trued and the problem did not come back. When they balance them they can see it right away.


Jason

 

Well, if its unevenly worn, the tire is pretty much comprimised and you need a new front tire. In fact, you might as well go with two new front tires as to keep a good balance and proper allignment. But before that, print out the allignment specs off of the Alfa Digest and make sure they are the same as whatever shop you're using. Honestly, any shop can do the allignment; it's pretty straightforward. Get all of your tires balanced as well and you should be set.

 

check the A frame bushings too

With worn bushings my symptoms were

1. Vibration developed at 65-70 mph
2. Severe inner tire wear

It was the pass side of the LS also.

 

With worn bushings my symptoms were

1. Vibration developed at 65-70 mph
2. Severe inner tire wear

It was the pass side of the LS also.

Good Point.
The inner tire wear could be the control arm bushing in front. passenger side seems to go more on these than drivers.
Will account for drifting, R/L turns push it into the bushing so you don't have an issues, just when it sits in the middle(going straight) if the bushing is toast.
J

 

I have a similar problem with my '95 Q. Have rotated the tires, no change. The vibration comes and goes and gets worse on deceleration. All front suspension parts have been replaced except shocks, inner tie rod ends, wheel bearings and steering rack.

 

Well, it turned out that the two front struts needed to be replaced, one was slightly bent. Also one of the front bushing was replaced. I have to have the car realigned, but the vibration at 65-70mph is history.